Little was known about L-glutamine (commonly referred to as glutamine) until research in the 1930s found it to be the most prevalent amino acid in the human body. Approximately 20 amino acids, classified as essential or nonessential, make up dietary protein. Glutamine is a nonessential amino acid (i.e., the body is able to synthesize it) contained in most dietary proteins. A healthy person consumes 5–10 grams of dietary glutamine daily and, therefore, usually does not need supplemental glutamine.